- #1

U154756

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A runner of mass m=36 kg and running at 2.9 m/s runs and jumps on the rim of a playground merry-go-round which has a moment of inertia of 404 kgm^2 and a radius of 2 m. Assuming the merry-go-round is initially at rest, what is its final angular velocity to three decimal places?

According to the back of the book, the answer is 0.381 rad/s; however, I can never come up with that answer.

I have tried the following formulas with no luck:

mvr = Iw

1/2mv^2 = 1/2Iw^2 (until I realized kinetic energy would not be conserved.)

I know it has something to do with conservation of angular momentum; however, I cannot seem to figure out the angular momentum of the runner before he jumps onto the merry-go-round. Any help would be greatly appreciated.